Heroin was first synthesized in 1874 by C. R. Alder Wright, an English chemist working at St. Mary’s Hospital Medical School in London.
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Wright’s invention did not lead to any further developments, and diacetylmorphine only became popular after it was independently re-synthesized 23 years later by another chemist, Felix Hoffmann. Hoffmann, working at the Aktiengesellschaft Farbenfabriken (today the Bayer pharmaceutical company) in Elberfeld, Germany